1. Field of the Invention
The present invention relates to a wireless controller, and more particularly, to an infrared pointing type wireless controller in which a carrier frequency signal for use in transmission of a signal is transmitted to a system main body which is an object of the pointing, a handset remote controller controls a reflection of the transmitted carrier frequency signal for producing a required code, and the main body receives a signal reflected from the handset remote controller for determining a pointed position according to intensities of the received signals.
2. Discussion of Related Art
FIGS. 1 through 3 illustrate a conventional infrared pointing type wireless controller as disclosed by the inventor under the same title as the present application in Korean Patent Application No. 92-12672. In particular, FIG. 1 schematically illustrates the conventional infrared pointing type wireless controller, FIG. 2 illustrates in detail the controller shown in FIG. 1, and FIG. 3 illustrates infrared sensors 21 through 21-3 located at four corners of a display screen.
As shown in FIG. 1, the conventional infrared pointing type wireless controller includes an infrared ray transmitting circuit 10 for transmitting infrared signals of a certain frequency, and a receiving and controlling circuit 20 for receiving the transmitted signals through receiving sensors 21.about.21-3 arranged at different positions on a display screen 11, calculating coordinates of a pointed position according to differences between intensities of the infrared signals received through each of the receiving sensors 21.about.21-3, and matching the pointed position with a position on the display screen 11.
The infrared ray transmitting circuit 10 includes a periodic pulse generator 12 for generating a remote control code signal in the form of periodic pulses by turning the switch SW on and off, a carrier signal generator 13 for generating a carrier signal, a current amplifier 14 for overlapping and amplifying the periodic pulses generated in the periodic pulse generator 12 and the carrier signal generated in the carrier signal generator 13, and infrared-emitting diodes 15 for transmitting the signal amplified by the current amplifier 14.
The receiving and controlling means 20 includes infrared ray receiving sensors 21.about.21-3 each arranged on the monitor screen 11 for receiving the signal transmitted from the infrared ray transmitting means 10, amplifying parts 22.about.22-3 for further amplifying the signals from the infrared ray receiving sensors 21.about.21-3, envelope detectors 23.about.23-3 for removing the carrier signal from the signals amplified by the amplifying parts 22.about.22-3 and for sensing an intensity level of the signal received by each of the infrared ray receiving sensors 21.about.21-3, a multiplexer 24, a sample-and-hold 25 and an analog-to-digital converter 26 connected in series for converting each of the intensity levels sensed by the envelope detectors 23.about.23-3 to digital data, a coordinate calculator 27 for receiving the digital data from the analog-to-digital converter 26 and for calculating coordinates of a position on the display screen 11 at which the infrared ray transmitting means 10 is pointed, a main processor 28 for matching the position on the display screen 11 to the calculated coordinates for displaying the point on the display screen 11 at which the infrared ray transmitting means 10 is pointed, and a control logic part 29 for providing timing signals necessary for operation of the receiving and controlling means 20. The infrared ray transmitting means 10 may be an infrared ray transmitter, such as a handset remote controller, and the receiving and controlling means 20 may be a system main body.
In the conventional infrared pointing type wireless controller having the aforementioned configuration, the infrared ray transmitting means 10 transmits an infrared signal toward a position on the display screen 11 having the infrared receiving sensors 21.about.21-3 mounted at four positions thereof. The intensity of the infrared signal as received by each of the infrared receiving sensors 21.about.21-3 is different.
More particularly, when the switch SW on the infrared ray transmitting means 10 is turned on, i.e., closed, the periodic pulse generator 12 generates periodic pulses until the switch SW is turned off, i.e., opened. These periodic pulses are overlapped by the carrier signal produced by the carrier signal generator 13 and amplified by the current amplifier 14. The current amplifier 14 sufficiently amplifies the overlapped periodic pulses and carrier signal to drive the infrared-emitting diodes 15 and thereby transmit the periodic pulses and the carrier signal as an overlapped infrared signal.
The infrared signal transmitted by the infrared-emitting diodes 15 is sensed by each of the infrared ray receiving sensors 21.about.21-3 in the receiving and controlling means 20. The outputs of the sensors 21.about.21-3 are then amplified by the amplifying parts 22.about.22-3.
The carrier signals are next removed from the signals amplified by the amplifying parts 22.about.22-3 by the envelope detectors 23.about.23-3. The resulting signals represent the intensities of the infrared signal as received by each of the infrared ray receiving sensors 21.about.21-3. Each of the intensity level signals is converted successively to digital data through the multiplexer 24, sample-and-hold 25, and analog-to-digital converter 26. From this digital data, the coordinate calculator 27 calculates coordinates on the display screen 11 at which the infrared ray transmitting means 10 is pointing at the present time. The coordinates calculated by the coordinate calculator 27 are entered into the main processor 28 which matches a point on the display screen 11 and the calculated coordinates and displays the present point on the screen 11.
Because the infrared ray transmitting means 10 is disposed in the handset remote controller, the foregoing conventional wireless controller generates the required carrier frequency signal and the remote control code signal in the handset remote controller itself and emits them by turning the infrared-emitting diodes 15 on and off. However, this process consumes a large amount of power, particularly in situations where two or more emitters are involved. As a result, the dry cell for the handset must be replaced frequently.